Exercise assisting apparatus

ABSTRACT

An exercise assisting apparatus has a seat with a contact surface of which position is varied within an adjustable range defined by a user&#39;s physique in order to successfully adjust the user&#39;s knee at a desired bent angle irrespective of the user&#39;s height. The seat  21  bears the buttock of the user M with the user&#39;s feet resting on a foot supporting surface on top of a foot stand  40 . The seat  21  is displaced by a seat driver  50  with a motor in a direction of varying the user&#39;s weight acting on the legs of the user M. The seat  21  is driven by an elevator mechanism  60  to move up and down together with the seat driver  50 . The elevator mechanism  60  moves the seat  21  in a direction which is restricted to a line inclined rearwardly and upwardly with respect to a vertical direction and deducted by a user of maximum physique and a user of minimum physique.

TECHNICAL FIELD

The present invention relates to a exercise assisting apparatus of apassive type wherein the weight of a user acting on the legs of the useris varied by using a drive source to displace a seat with the user'sfeet resting on a foot supporting surface and the user's buttockssupported by the seat.

BACKGROUND ART

Japanese Patent Application Publication No. 2005-58733 (PatentDocument 1) and Japanese Patent Application Publication No. 2007-89650(Patent Document 2) propose an exercise assisting apparatus wherein athigh muscle group is tensed and relaxed with hardly any extension ofthe knee, by displacing a seat with the user's feet resting on a footsupporting surface and the user's buttocks supported on a contactsurface of the seat. This exercise assisting apparatus varies the user'sweight acting on the user's legs by changing the ratio of the user'sweight supported by a seat by displacing the position of the seat.

By an operation of this kind, the load is reduced compared to a casewhere the whole weight acts on the user's legs, and the thigh musclesare contracted with hardly any extension of the knee, whereby, forexample, even a user having knee pain such as a patient with diabetes isable to strengthen the muscle group of the thigh, and furthermore sincethe muscle group of the thigh has a large volume, it is also expected toobtain a contribution to improvement in lifestyle-related diseases, byglucose metabolism associated with the muscular contraction. Moreover,by using a drive source to displace the seat, the user is able toexercise passively without exerting muscular force spontaneously, andtherefore the load is light and consequently the apparatus can be usedeven by person's having a low capacity of movement.

Incidentally, an exercise assisting apparatus having the compositiondescribed above tenses and relaxes the thigh muscle group by changingthe weight of the user that acts on the user's legs, with virtually noextension of the knees, and therefore the knee bending angle is animportant factor in performing exercise effectively. As the analogy of asquatting movement readily shows, the load acting on the muscle group ofthe thigh varies with the knee bending angle. Furthermore, in the caseof a user with knee pain, if a load acts on the user's knee while theknee is bent to a certain degree, the user often experiences pain andthe bending angle must be restricted in order to make an apparatususable by persons of this type as well.

At the present time, experimental results have been obtained indicatingthat the exercising effect is high and knee pain is not liable to occur,if the knee bending angle (in practice, the measured angle is thatformed between the thigh and the lower leg on the front side of theknee) is set to 140 degrees, and hence this angle has been set as anappropriate angle.

In the apparatus described in Patent Document 2, it is proposed that theposition of the seat is made adjustable in such a manner that the kneebending angle becomes the appropriate angle, and the position of theseat is adjusted automatically in accordance with an input parameterrelating to the user's height. The position of the seat is adjustable inat least one of the vertical direction and the forward/rearwarddirection, and the horizontal distance from the foot position becomesgreater if the seat is raised, while the horizontal distance from thefoot position becomes smaller if the seat is lowered.

Patent Document 2 describes making the knee bending angle adjustable toan appropriate angle by adjusting the position of the seat, and suggestsrelating the position of the seat at which the knee bending anglebecomes an appropriate angle to a parameter corresponding to the user'sheight, but does not provide a theory about how to change the seatposition with respect to the user's height in order to achieve a desiredknee bending angle. Consequently, in the composition described in PatentDocument 2, it is not clear how the user's height and the position atwhich the user's buttocks are supported by the seat are related in orderto set the knee bending angle to a desired angle.

DISCLOSURE OF THE INVENTION

The present invention is devised in view of the above reasons. An objectin this invention is to provide an exercise assisting apparatus which isconfigured to adjust the knee bending angle to a desired angleregardless of the user's height. The adjustment is performed byspecifying the range of adjustment of the position of a contact surfaceof the seat on the basis of the theory of the relationship of theposition of the contact surface which supports a user's buttocks in aseat, the knee bending angle, and the user's height.

The exercise assisting apparatus relating to the present inventioncomprises: a seat having a contact surface configured to support thereona buttock of a user with the user's feet resting on a predetermined footsupporting surface; a seat driving mechanism configured to use a drivingsource for displacing the seat in a direction of varying the user'sweight acting on the user's legs; and an elevator mechanism configuredto adjust a vertical position and a forward/rearward position of thecontact surface of the seat in order to keep a user's knee bending angleat a prescribed angle while the user is sitting on the seat held at areference position with the user's feet placed on a predeterminedposition on the foot supporting surface. The elevator mechanism isconfigured to adjust the position of the contact surface of the seatmember within a restricted range along a line which is inclinedrearwardly and upwardly with respect to a vertical direction and isdeduced by a user of maximum physique and a user of minimum physique.Therefore, it is possible to restrict theoretically the range ofadjustment of the position of the contact surface of the seat, and as aresult of this, adjustment which keeps the knee bending angle at adesired angle can be performed reliably, irrespectively of the height ofthe user.

Desirably, the elevator mechanism is composed so as to comprise anelevator driver for displacing the position of the seat with respect toa base held at a fixed position. The elevator driver is configured tovary the position of the seat linearly along a path inclined rearwardlyand upwardly at a predetermined angle within a vertical plane in whichthe seat is allowed to move vertically and forward/rearward. Since theelevator mechanism varies the position of the seat linearly in this way,then the elevator mechanism can be achieved by means of a simplemechanism which moves the seat linearly.

Desirably, the elevator driver comprises a fixed member secured to thebase, a movable member configured to move along a linear path relativeto the fixed member and support the seat, and a drive motor configuredto move the movable member towards and away from the fixed member. Inthis case, the driving force of the drive motor can be used to raise andlower the seat, and the position of the seat can be adjusted even whenthe user's buttocks are supported on the seat.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view showing an exercise assisting apparatusrelating to one embodiment of the present invention;

FIG. 2 is a schematic plan view of the exercise assisting apparatus;

FIG. 3 is a diagram describing the operational principles of theexercise assisting apparatus;

FIG. 4 is an exploded perspective diagram of the exercise assistingapparatus;

FIG. 5 is an exploded perspective diagram of a seat driver used in theexercise assisting apparatus; and

FIG. 6 is a side view diagram of a seat driver used in the exerciseassisting apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

As shown in FIG. 1 and FIG. 2, the exercise assisting apparatus relatingto one embodiment of the present invention has a base 10 which isdisposed in a fixed position on a floor, or the like, and provided ontop of this base 10 are: a seat support base 20 having a seat 21 whichsupports the buttocks of a user M provided on the upper end thereof, anda handle post 30 having a handle 31 which the user M grips with his orher hands as necessary provided on the upper end thereof. A foot stand40 is arranged on the base 10 so as to be located between the seatsupport base 20 and the handle 30. The foot stand 40 has the uppersurface of which forms a foot supporting surface 40 a. The foot stand 40restricts the position of the user's feet by means of the user M placinghis or her feet on the foot supporting surface 40 a.

Provided on the seat support base 20 are: a seat driver 50 which causesthe seat 21 to oscillate, and an elevator mechanism 60 which raises andlowers the seat 31 and the seat driver 50 with respect to the base 10.The composition of the seat driver 50 and the elevator mechanism 60 isdescribed below.

The seat driver 50 operates the drive source to swing the seat 21,thereby the seat driver 50 changing the weight of the user M who sits onthe contact surface 21 a of the seat 21 and who places the feet on thesupporting surface 40 a of the foot stand 40. As a result, the weight ofthe user M that acts on the user's knee is changed. In other words, thebody weight of the user M is supported by the buttocks and the legs in adistributed fashion. In this context, when the position of the user'sbuttock is varied, the weight supported by the buttocks is increased anddecreased. According to variation of the weight supported by thebuttock, the weight acting on the legs is changed.

When the knees are bent by a prescribed angle, then if the ratio of thebody weight supported by the seat 21 is decreased, the load acting onthe thighs of the user M is increased and the muscle group of the thighregion can be made to contract, similarly to bending the knees byperforming a squat movement. In other words, when the seat 21 is causedto oscillate by the drive source, the thigh muscle groups repeat atensing and relaxing action by means of a passive movement which is nota spontaneous movement of the user M. In other words, it is possibleprincipally to exercise the thigh region by means of the seat driver 50causing the seat 21 to oscillate.

The direction of oscillation of the seat 21 is desirably set in such amanner that no shearing force acts on the knee joints. When the buttocksof the user M are supported by the contact surface 21 a of the seat 21,the user M's feet naturally adopt an attitude where the distance betweenthe toe tips is greater than the distance between the heels, as shown inFIG. 2, and the angle of opening θ2 between the feet can be determinedfrom the position where the feet are placed on the foot stand 40.Therefore, it is possible to exercise without applying a shearing forceto the knee joints by oscillating the seat 21 in a direction followingthe central lines that link the heels and the tips of each foot when theuser's feet are placed on the foot stand 40. In other wards, it ispreferred to provide a time period during which the seat 21 movesobliquely rightwards and forwards and a time period during which theseat 21 moves obliquely leftwards and forwards when the seat 21 movesforward from the rear end position in the range of oscillation.Consequently, it is possible to make the user's weight act respectivelyon the thigh area of the left legs and the right legs, without applyinga shearing force to the knee joints.

In the example shown in FIG. 1, the contact surface 21 a which is theupper surface of the seat 21 is a substantially horizontal surface.However, the exercise which stimulates muscular contraction of the thighmuscle group is performed by changing the weight of the user M that isacting on the user's legs. Therefore, it is desirable that the contactsurface 21 a of the seat 21 making contact with the buttocks of the userM should be inclined downwardly in the forward direction of thedirection of oscillation of the seat 21. In other words, desirably, theportion which supports the right buttock area of the user M in the frontend portion of the seat 21 in inclined obliquely downwards in therightward and forward direction. Similarly, desirably, the portion whichsupports the left buttock area of the user M is inclined obliquelydownwards in the leftward and forward direction. If a shape of this kindis adopted, then when the seat 21 is moved forward from the rear endposition of the oscillation range, the user's weight acting on the legsis liable to increase and the exercising effect can be raised.

A control and display apparatus 32 is provided in the central part ofthe handle 31 on the upper end portion of the handle post 30. Thecontrol and display apparatus 32 is provided for operation of issuinginstructions in respet of the operation of the seat driver 50 and theelevator mechanism 60, and for display of measures indicating the amountexercise, and the like. The user M is able to stabilize the position ofhis or her upper body by gripping the handle 31.

The structure of the handle support base 20 is described in more detailbelow. As shown in FIG. 4, the handle support base 20 has a hollowsupporting column 22 which is erected on the base 10, and the lower endportion of the elevator mechanism 60 is accommodated inside thesupporting column 22. The elevator mechanism 60 has an elevator base 61which ascends and descends slidably with respect to the supportingcolumn 22, and the seat driver 50 is mounted on the upper end of theelevator base 61. Consequently, the seat driver 50 is able to move withrespect to the base 10, together with the seat 21.

The center line of the supporting column 22 is a straight line which isinclined rearwardly with respect to the vertical direction (in otherwords, inclined rearwardly and upwardly), and by means of the elevatorbase 61 sliding inside the supporting column 22, the position of thecontact surface 21 a of the seat 21 can be adjusted in a single straightline following the center line of the supporting column 22, in thevertical direction. In other words, the position of the contact surface21 a of the seat 21 is adjusted in the forward/rearward directionsimultaneously with being adjusted in the vertical direction. Inaddition, the further the position of the contact surface in the upwarddirection, the further its position in the rearward direction. The angleformed between the center line of the supporting column 22 and the base10 is described hereinafter.

The elevator base 61 is driven to ascend and descend by an elevatordriver 62 which comprises a drive motor 63. The elevator driver 62comprises, in addition to the drive motor 63, a column-shaped fixedmember 64 which is fixed to the base 10, and a movable member 65 whichcomprises a ball screw that screws into the fixed member 64, and employsa composition whereby the movable member 65 is advanced and retractedwith respect to the fixed member 64 by decelerating the rotation of thedrive motor 63 so as to rotate the movable member 65. The elevator base61 is installed on the upper end portion of the movable member 65, andascends and descends with the advancing or retreating movement of themovable member 65 with respect to the fixed member 64.

The elevator base 61 comprises a seating 61 a and a pair of guide plates61 b. The seat driver 50 is mounted on the seating 61 a. A pair of theguide plates are provided on the lower surface of the seating 61 a. Theupper end portion of the movable member 65 in the elevator driver 62 iscoupled to the lower surface side of the seating 61 a. Furthermore,rollers 61 c are installed on the outer surfaces of the guide plates 61b, and by guiding these rollers 61 c in rail sections 22 a provided onthe inner surface of the supporting column 22, it is possible to movethe elevator base 61 smoothly with respect to the supporting column 22.A sensor which determines the amount of advance or retreat of themovable member 65 with respect to the fixed member 64 is provided, andthe rotation of the drive motor 63 is controlled in such a manner thatthe value determined by the sensor coincides with a target valuespecified in accordance with an input via the display and control unit32. However, since this composition is not an essential feature, furtherdescription thereof is not included here.

A tubular elevator cover 66 is attached to the seating 61 a of theelevator base 61. The lower end portion of the elevator cover 66overlaps with the outer surface of the supporting column 22 in the rangeof extension and contraction of the elevator driver 62, and by thismeans the elevator base 61 is not exposed to the exterior even when theelevator driver 62 is extended by the maximum amount. Moreover, amechanical unit cover 67 formed from a cloth-like soft material isattached to the seating 61 a of the elevator base 61. The mechanicalunit cover 67 prevents the seat driver 50 from being exposed to theexterior by covering the portion between the seating 61 a and the seat21.

Next, the seat driver 50 is described with reference to FIG. 5 and FIG.6. The seat driver 50 constitutes a mechanism which causes the seat 21to oscillate together with the seating 61 a of the elevator base 61. Theseat driver 50 is installed axially on a front and rear pair of axleplates 51 a, 51 b, and axles 52 a, 52 b. The front and the rear pair ofaxle plates 51 a, 51 b are provided in an upright fashion on the uppersurface of the seating 61 a. The front and rear axles 52 a, 52 b aredisposed coaxially, and by means of the seat driver 50 rotating aboutthese axles 52 a, 52 b, the seat 21 which is coupled to the seat driver50 can be caused to oscillate leftwards and rightwards (in thedirections indicated by arrow N in FIG. 4).

The seat driver 50 comprises a front and rear pair of frame plates 53 a,53 b, and these two frame plates 53 a, 53 b are coupled via a left andright-hand pair of frame side plates 54 a, 54 b. The lower end portionsof a front link 55 and a rear link 56 which rotate about an axis in theleft/right direction are installed axially by means of axles 55 a, 56 aon the two frame side plates 54 a, 54 b, and the upper end portions ofthe front link 55 and the rear link 56 are installed axially on a baseplate 57 by means of axles 55 b and 56 b. Here, the upper end portion ofthe rear link 56 is installed axially on a bearing plate 57 a which isfixed to a base plate 57 rather than being axially installed directly onthe base plate 57.

The range of movement of the base plate 57 is restricted in such amanner that the front end portion of the base plate 57 moves through acircular arc centered on the axle 55 a, and the rear end portion of thebase plate 57 moves through a circular arc centered on the axle 56 a.Here, the rear link 56 is formed to a longer dimension than the frontlink 55, and hence the front end portion and the rear end portion of thebase plate 57 have different radii of curvature, whereby the angle ofinclination of the upper surface changes as the base plate 57 movesforwards and rearwards. More specifically, if the position shown in FIG.6 is taken as the rear end position of the range of movement in theforward/rearward direction, then as the base plate moves forward, thefront end portion of the base plate 57 descends relatively with respectto the rear end portion thereof, thereby increasing the angle ofinclination of the upper surface. Conversely, if the base plate is movedrearwards from the front end position, the front end portion of the baseplate 57 rises upwards relatively with respect to the rear end portion,thereby reducing the angle of inclination of the upper surface. In otherwords, the seat 21 can be moved in the forward/rearward direction (thedirection indicated by arrow X in FIG. 4). FIG. 4 depicts linearmovement, but in actual practice, because the angle of inclination ofthe forward/rearward direction changes, then the displacement combines alinear movement and a rotational movement in the forward/rearwarddirection.

The motor 71 which is a drive source for oscillating the base plate 57with respect to the base plate 61 a is held by both frame side plates 54a and 54 b. Furthermore, the motor 71 is disposed vertically in such amanner that the output shaft thereof projects in the upward direction. Aworm gear 72 is coupled to the output shaft of the motor 71. A firstshaft 73 and a second shaft 74 are supported on the frame side plates 54a and 54 b, and a worm wheel 75 which meshes with the worm gear 72 isprovided on the first shaft 73. A gear 76 is also provided on the firstshaft 73 and the gear 76 meshes with a gear 77 which is provided on thesecond shaft 74.

Eccentric cranks 78 which rotate together with the first shaft 73 areattached respectively to either end of the first shaft 73. One end of anarm link 79 is axially installed respectively on each eccentric crank78, and the other ends of the arm links 79 are axially installedrespectively on axle pins 55 c which project to the left and right ofthe front link 55.

By means of this composition, when the motor 71 turns and the firstshaft 73 rotates, the front link 55 moves back and forth reciprocally inthe forward/rearward direction about the axles 55 a due to the eccentriccranks 78 and the arm links 79, and the front portion of the base plate57 oscillates in the forward/rearward direction about the axles 55 a(the direction indicated by arrow X in FIG. 4). Furthermore, after therear link 56 has turned about the axles 56 a, the angle of inclinationof the upper surface changes with the movement of the base plate 57 inthe forward/rearward direction.

On the other hand, an eccentric pin 74 a is provided in a standingfashion on one end portion of the second shaft 74, and one end portionof an eccentric rod 80 is installed axially on this eccentric pin 74 a.The other end portion of the eccentric rod 80 is coupled in anoscillatable fashion to a coupling piece 81 which is attached to theseating 61 a. The pin 74 a and the eccentric rod 80 may be provided oneither the left or right-hand side of the seat driver 50.

By means of this composition, if the motor 71 is turned and the secondshaft 74 is rotated via the first shaft 73, then the height position ofthe eccentric pin 74 a with respect to the seating 61 a changes with thepin 74 a and the eccentric rod 80, and as a result, the base plate 57oscillates leftwards and rightwards about the axles 52 a and 52 b (thedirection indicated by arrow N in FIG. 4).

A brushless DC motor, or the like, is used for the motor 71, and a DCmotor is also used for the drive motor 63. Here, since the motor 63 isdisposed in a space which is surrounded by the frame plates 53 a, 53 b,the frame side plates 54 a, 54 b, the seating 61 a and the base plate57, and since the gears 75 to 77 are also disposed in the same space,then the seat driver 50 is compact.

Basically, the seat driver 50 moves the seat 21 in a rightward forwardand downward direction and a leftward forward and downward direction.However, in the composition described above, by appropriately settingthe gear ratios of the gears 76 and 77, and the phase differentialbetween the eccentric crank 78 and the eccentric pin 74 a, then apartfrom a V-shaped path of movement of the seat 21 (where two reciprocalforward and rearward movements are performed during one reciprocalmovement in the left/right direction), the path of movement of the seat21 can also be set to a W shape (where four reciprocal forward andrearward movements are performed during one reciprocal movement in theleft/right direction), or a figure of eight shape (where two reciprocalforward and rearward movements are performed during one reciprocalmovement in the left/right direction and the rear end positions areskewed to the left and right-hand sides), and so on.

The operation and halting of the drive motor 63 and the motor 71 arecommanded by operating the control and display apparatus 32. In otherwords, a control section for instructing the operation or halting of themotor 71 and the speed of revolution of the motor 71 is provided in thecontrol and display apparatus 32, and hence the exercise time period andthe exercise intensity can be specified. Furthermore, a control sectionfor raising or lowering the seat 21 is provided in such a manner thatthe knee bending angle assumes an appropriate angle. The control sectionand the display section provided in the control and display apparatus 32are connected to the operation of the motor 71 and the drive motor 63 bymeans of a control circuit (not illustrated).

In the exercise assisting apparatus described above, it is necessary tokeep the knee bending angle at an appropriate angle in order to promotecontraction of the thigh muscle group without causing knee pain, even inthe case of a user M who suffers from knee pain. That is, the exerciseassisting apparatus gives the movement of changing the user's weightacting on the thigh to the user having the knee angle at a prescribedangle. When the user uses the exercise assisting apparatus, the user'sfeet are fixed in position by resting on the foot stand 40. Here, it isdesired that the knee joint is aligned along the vertical direction tothe foot joint in order to increase the load acting on the thigh.Therefore, due to these restricting conditions, the knee bending angleis governed by the position of the seat 21. Leg dimensions vary betweendifferent individuals, and change significantly with the height of theuser M.

As described above, the height position of the seat 21 is adjustable bymeans of the elevator mechanism 60, and furthermore, by moving the seat21 in a straight line which is inclined rearwards with respect to thebase 10, the elevator mechanism 60 adjusts the position of the contactsurface 21 a of the seat 21 in such a manner that the further thecontact surface moves upwards, the further the contact surface ispositioned rearwards.

The direction in which the elevator mechanism 60 moves the seat 21 isdescribed with reference to FIG. 3. It is supposed that with the user'sfeet resting on the foot stand 40, the straight line linking the footjoint J2 and the knee joint J1 (in other words, the shinbone) coincideswith the vertical direction. Furthermore, it is supposed that the angleof opening θ2 between the two feet (see FIG. 2) when the feet areresting on the foot stand 40 is 20 degrees. Moreover, the knee bendingangle is θ1 (see FIG. 1), the distance between the hip joint J3 and theknee joint J1 is L1, the distance from the upper surface of the footstand 40 to the knee joint J1 is L2, and the angle formed between thedirection of movement of the seat 21 and the horizontal plane (in otherwords, the angle formed between the central line of the support column22 and the base 10) is φ.

If these parameters are used, then at the position P1 where the buttocksmake contact with the contact surface 21 a of the seat 21 (theintersection of the plumb line from the center of gravity of the user'strunk with the contact surface 21 a), the horizontal distance X betweenposition P1 and the foot joint J2 and the height Y of position P1 fromthe upper surface of the foot stand 40 can be represented by thefollowing expressions.

X=L1·sin(180°−θ1)·cos(θ2/2)

Y=L1·cos(180°−θ1)+L2−L3

L3 is the distance between the position P1 and the hip joint J3. Forexample, if the height of the user M is in the range of 140 to 170 cm,then by adopting standard values for the distances L1 and L2, it ispossible to derive the angle φ by calculation. In other words, takingthe differences in the distances L1 and L2 due to difference in physiqueas ΔL1 and ΔL2 respectively, it is possible to determine the angle φ ifthe maximum value and minimum value of the difference in physique areemployed.

When calculation was made using the value for a female aged 65 to 79(standard value) as the minimum physique value, and using the value fora male aged 65 to 79 (standard value) as the maximum physique value,then it was possible to identify 75 degrees as the angle φ whereby theknee bending angle could be kept to 140 degrees in both persons. Inother words, when the straight line passing through the positions P1determined in respect of the maximum and minimum physiques of the user Mwas found, it was seen that this line was inclined rearwards withrespect to the vertical direction and formed an angle of 75 degrees withrespect to the horizontal surface.

Here, since the angle γ is determined from the positions P1 which arespecified for the two points relating to a minimum physique and amaximum physique, then although compatibility with a user M of anotherphysique is not necessarily guaranteed, the aforementioned distances L1and L2 are predicted to change in a substantially linear fashion withrespect to the user's height and therefore linear interpolation betweenthe maximum value and the minimum value is possible. Furthermore, sincelinear interpolation is possible, then as described above, it ispossible to employ a simple mechanism which performs linear movement asthe elevator mechanism 60. Here, it is also possible to determine threeor more points in respect of differences in physique, and to trace thepath of movement of the seat 21 by the elevator mechanism 60 as a curve.

1. An exercise assisting apparatus comprising: a seat having a contactsurface configured to support thereon a buttock of a user with theuser's feet resting on a predetermined foot supporting surface; a seatdriving mechanism configured to use a driving source for displacing saidseat in a direction of varying the user's weight acting on the user'slegs; and an elevator mechanism configured to adjust a vertical positionand a forward/rearward position of said contact surface of the seat inorder to keep a user's knee bending angle at a prescribed angle whilethe user is sitting on the seat held at a reference position with theuser's feet placed on a predetermined position on said foot supportingsurface; wherein said elevator mechanism is configured to adjust theposition of the contact surface of the seat member within a restrictedrange along a line which is inclined rearwardly and upwardly withrespect to a vertical direction and is deduced by a user of maximumphysique and a user of minimum physique.
 2. An exercise assistingapparatus as set forth in claim 1, wherein said elevator mechanismcomprises an elevation driver for displacing the position of said seatrelative to a base held at a fixed position, said elevation driver beingconfigured to vary the position of said seat linearly along a pathinclined rearwardly and upwardly at a predetermined angle within avertical plane in which said seat is allowed to move vertically andforward/rearward.
 3. An exercise assisting apparatus as set forth inclaim 2, wherein said elevator driver comprises a fixed member securedto said base, a movable member configured to move along a linear pathrelative to said fixed member and support said seat, and a drive motorconfigured to move said movable member towards and away from said fixedmember.